A convenient synthesis of enantiopure (4aS,7aR)-1,4,4a,7a-tetrahydrocyclopenta[c]pyran-3,7-dione

The title compound, as the new chiral building block for bioactive cyclopentenones, was prepared in 8 steps with 15% overall yield. The key steps involve selective homologation in intermediate [(1S,2R,5R)-5-trimethysilylcyclopent-3-ene- 1,2-diyl]dimethanol by regioselective silylation followed by oxidation and the Wittig reaction.